5.7 Bravo III again

torombolo

torombolo

Petty Officer 2nd Class
Joined
Mar 15, 2012
Messages
151
Morning members!!

I have a MOnterey 262 (2001) with a Mercruiser 5.7 and a Bravo III dual prop. back in june I had to replace the engine coupler that went bad gave the Bravo a rutine maintenance , seals, lube etc. and after that it worked good, I have used the boat only 4 or 5 times since then, the thing is the Bravo is at it AGAIN.
Scenario:
My engine RPM's 3500
GPS Speed 9 mph, tops
No wind, not chiopy either
After noticing the lack of push wend down to 2000 RPM's and back to port

I think there is some play in my props could this be?
Are there any bushings or anything that the props might be slipping?

Thank you in advance for any tips and help.
 
S

ssb33r

Seaman Apprentice
Joined
Aug 23, 2009
Messages
36
Re: 5.7 Bravo III again

Was the drive oil black when you drained it?? Did it drop off plane without the rpm changing?? Really the only things to slip are the coupler (youd smell burnt rubber at 3k) and the cone clutch
 
H

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: 5.7 Bravo III again

torombolo said:
Morning members!!

I have a MOnterey 262 (2001) with a Mercruiser 5.7 and a Bravo III dual prop. back in june I had to replace the engine coupler that went bad gave the Bravo a rutine maintenance , seals, lube etc. and after that it worked good, I have used the boat only 4 or 5 times since then, the thing is the Bravo is at it AGAIN.
Scenario:
My engine RPM's 3500
GPS Speed 9 mph, tops
No wind, not chiopy either
After noticing the lack of push wend down to 2000 RPM's and back to port

I think there is some play in my props could this be?
Are there any bushings or anything that the props might be slipping?

Thank you in advance for any tips and help.
Click to expand...

Howdy,


If you have previously replaced the coupler, the engine is REALLY turning 3500, and you're only going 9 mph, it's likely your coupler has failed again.

This could be due to a poor alignment the first (and second) time or a rotten transom, and/or stringers/engine mounts.

Bravo III propellers have a "direct" coupling to the shafts. (no bushings)

Regards,


Rick
bravoIIIa.gif
 
smitty28

smitty28

Seaman Apprentice
Joined
Apr 28, 2009
Messages
39
Re: 5.7 Bravo III again

I would say though, if the coupler really was failing and the engine was running at 3500 RPM and youre only goin 9 mph, I would think you would see tons of smoke and a burnt rubber smell comin from the bilge.. Many years back before I knew the importance of engine alignment, I installed a new engine in one of my boats, never aligned it and the coupler smoked like a leaf fire.
 
torombolo

torombolo

Petty Officer 2nd Class
Joined
Mar 15, 2012
Messages
151
Re: 5.7 Bravo III again

There was no smoke or burn rubber smell from the bilge, I remember when it happened the first time how it dropped from plane and loss of power. also the sound it made like when a belt slips. This time had no push from the get go, no wierd noise, no smell.
Im starting to hate I/O
 
C

cruzn

Cadet
Joined
Feb 10, 2011
Messages
8
Re: 5.7 Bravo III again

torombolo said:
There was no smoke or burn rubber smell from the bilge, I remember when it happened the first time how it dropped from plane and loss of power. also the sound it made like when a belt slips. This time had no push from the get go, no wierd noise, no smell.
Im starting to hate I/O
Click to expand...

So what happens if you push the thottle on up beyond 3500? Get on plane, speed increase? Are you sure the boat tach is accurate (could be 1000 rpm off?) Same prop pitch as before? Dings, bent blade(s)? A 26 footer w/a 5.7 should be sufficient but any other problem (fuel supply, dropped cylinder ignition, bad coil, timing off, etc) could also be the cause of lost performance.
 
S

ssb33r

Seaman Apprentice
Joined
Aug 23, 2009
Messages
36
Re: 5.7 Bravo III again

again how black was the oil?? Did it smell burnt or anything?? Any brass specks in it?? Really starting to sound like the cone clutch in the top end.
 
torombolo

torombolo

Petty Officer 2nd Class
Joined
Mar 15, 2012
Messages
151
Re: 5.7 Bravo III again

RPM's go up just find, even is the tach was 1000 rpms off, still I can accelerate WOT and feel also hear the engine going up. It does not get on plane if I go over 3500. The oil was not burned at all a little water due to a little hole in the other thank the coupler everything else is still the same, no bents, fresh fuel, timing should be good since it adles and accelerates withput a hitch.

Also no there were no specks
 
torombolo

torombolo

Petty Officer 2nd Class
Joined
Mar 15, 2012
Messages
151
Re: 5.7 Bravo III again

Sorry for the rant, itskind of frustrating twice in a year
 
S

ssb33r

Seaman Apprentice
Joined
Aug 23, 2009
Messages
36
Re: 5.7 Bravo III again

so there is a very limited number of parts that can cause your issue, the coupler but you should be able to smell that and see some rubber powder in the bilge, the shift cable may be out of adjustment, the shift cam and yoke may be worn enough that it cant pull it into gear, or the shift linkage could be worn out and cant pull the cam far enough to get it into gear
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 5.7 Bravo III again

Are you saying that the max rpm you can get out of the engine is 3500 rpm? If so, that is not a coupler problem, you have and engine running problem.
If a coupler was spun, first you would get very high rpm and you would never get to 9 mph.
 
torombolo

torombolo

Petty Officer 2nd Class
Joined
Mar 15, 2012
Messages
151
Re: 5.7 Bravo III again

Morning, my RPM's are fine, it goes up to 4000 I just always cruise at 3200 tops. The thing is th first time it happened I heard it when it sqeel or something it was a loud noise this time no smell or anything. Clutch sounds like an option guess the only way to really know would take the boat aot of the water and have at it
 
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